Guidelines on reporting treatment conditions for emerging technologies in food processing.

In the last decades, different non-thermal and thermal technologies have been developed for food processing. However, in many cases, it is not clear which experimental parameters must be reported to guarantee the experiments' reproducibility and provide the food industry a straightforward way to scale-up these technologies. Since reproducibility is one of the most important science features, the current work aims to improve the reproducibility of studies on emerging technologies for food processing by providing guidelines on reporting treatment conditions of thermal and non-thermal technologies. Infrared heating, microwave heating, ohmic heating and radiofrequency heating are addressed as advanced thermal technologies and isostatic high pressure, ultra-high-pressure homogenization sterilization, high-pressure homogenization, microfluidization, irradiation, plasma technologies, power ultrasound, pressure change technology, pulsed electric fields, pulsed light and supercritical CO2 are approached as non-thermal technologies. Finally, growing points and perspectives are highlighted.

Ultrasound-assisted production of alcoholic beverages: From fermentation and sterilization to extraction and aging.

Ultrasound is sound waves above 20 kHz that can be used as a nonthermal ''green'' technology for agri-food processing. It has a cavitation effect, causing bubbles to form and collapse rapidly as they travel through the medium during ultrasonication. Therefore, it inactivates microorganisms and enzymes through cell membrane disruption with physicochemical and sterilization effects on foods or beverages. This emerging technology has been explored in wineries to improve wine color, taste, aroma, and phenolic profile. This paper aims to comprehensively review the research on ultrasound applications in the winery and alcoholic beverages industry, discuss the impacts of this process on the physicochemical properties of liquors, the benefits involved, and the research needed in this area. Studies have shown that ultrasonic technology enhances wine maturation, improves wine fermentation, accelerates wine aging, and deactivates microbes while enhancing quality, as observed with better critical aging markers such as phenolic compounds and color intensity. Besides, ultrasound enhances phytochemical, physicochemical, biological, and organoleptic properties of alcoholic beverages. For example, this technology increased anthocyanin in red wine by 50%. It also enhanced the production rate by decreasing the aging time by more than 90%. Ultrasound can be considered an economically viable technology that may contribute to wineries' waste valorization, resource efficiency improvement, and industry profit enhancement. Despite numerous publications and successful industrial applications discussed in this paper, ultrasound up-scaling and applications for other types of liquors need further efforts.

The Impact of Hanseniaspora vineae Fermentation and Ageing on Lees on the Terpenic Aromatic Profile of White Wines of the Albillo Variety.

Hanseniaspora vineae is a non-Saccharomyces yeast that has a powerful impact on the sensory profile of wines. Its effect on the aromatic profile of non-aromatic grape varieties, such as Albillo Mayor (Vitis vinifera, L), during vinification is a useful biotechnology to improve sensory complexity. Fermentation in steel barrels using Hanseniaspora vineae and sequential inoculation with Saccharomyces cerevisiae have been used to study the formation of terpenes and cell lysis in the production of Albillo white wines. The GC-MS analysis profile shows a significant effect of H. vineae fermentation on the contents of terpenes (≈×3), mainly in linalool (>×3), ß-citronellol (>×4), geraniol (>×2) and α-terpineol (≈×2). The contents of several polyoxygenated terpenes and some volatile phenols with a spicy aroma were increased during fermentation. In summary, Hanseniaspora vineae releases a large number of cell wall polysaccharides during fermentation that affect wine palatability and structure. Hanseniaspora vineae is a powerful bio-tool to enhance the fruitiness, floral notes and freshness in non-aromatic white varieties.

Non-Saccharomyces as Biotools to Control the Production of Off-Flavors in Wines.

Off-flavors produced by undesirable microbial spoilage are a major concern in wineries, as they affect wine quality. This situation is worse in warm areas affected by global warming because of the resulting higher pHs in wines. Natural biotechnologies can aid in effectively controlling these processes, while reducing the use of chemical preservatives such as SO2. Bioacidification reduces the development of spoilage yeasts and bacteria, but also increases the amount of molecular SO2, which allows for lower total levels. The use of non-Saccharomyces yeasts, such as Lachancea thermotolerans, results in effective acidification through the production of lactic acid from sugars. Furthermore, high lactic acid contents (>4 g/L) inhibit lactic acid bacteria and have some effect on Brettanomyces. Additionally, the use of yeasts with hydroxycinnamate decarboxylase (HCDC) activity can be useful to promote the fermentative formation of stable vinylphenolic pyranoanthocyanins, reducing the amount of ethylphenol precursors. This biotechnology increases the amount of stable pigments and simultaneously prevents the formation of high contents of ethylphenols, even when the wine is contaminated by Brettanomyces.

Effect of Different Clarification Treatments on the Volatile Composition and Aromatic Attributes of 'Italian Riesling' Icewine.

The aim of this study was to evaluate the influence of clarification treatments on volatile composition and aromatic attributes of wine samples. 'Italian Riesling' icewines from the Hexi Corridor Region of China were clarified by fining agents (bentonite (BT) and soybean protein (SP)), membrane filtration (MF), and centrifugation (CF) methods. The clarity, physicochemical indexes, volatile components, and aromatic attributes of treated wines were investigated. Both the fining agents and mechanical clarification treatments increased the transmittance and decreased the color intensity of icewine samples. Bentonite fining significantly influenced the total sugar content, total acidity and volatile acidity. Total acidity decreased 2-3.5% and volatile acidity 2-12%. MF showed the greatest influence on total phenol content, decreasing the initial content by 12%, while other treatments by less than 8%. Volatile analysis indicated that both the categories and contents of volatile compounds of wine samples decreased. MF treatment showed the most significant influence, while SP fining showed much lower impact. Odor activity values indicated the compound with the highest odor activity in Italian Riesling icewines was ß-damascenone. For this compound, BT and SP did not show significant differences, however, in MF and CF it decreased by 20% and 63%, respectively. Furthermore, with high impact on aroma were: ethyl hexanoate which reduced by 20-80% especially in MF; rose oxide which extremely reduced in MF and undetected in BT, SP, and CF; isoamyl acetate which reduced by 3-33% and linalool decreased by 10-20% and undetected for BT. Principle component analysis indicated that icewine clarified by different methods could be distinguished and positively correlated with odor-active compounds. Floral and fruity were the dominant aroma series in icewine samples followed by fatty, earthy, spicy, vegetative and pungent flavor. The total odor active value of these series significantly (p < 0.5) decreased in different clarification treatments. Sensory evaluation showed similar results, but the SP and CF wine samples achieved better sensory quality. This study provides information that could help to optimize the clarification of ice wines.

Influence of Saccharomyces and non-Saccharomyces Yeasts in the Formation of Pyranoanthocyanins and Polymeric Pigments during Red Wine Making.

Yeast are able to modulate many sensory parameters of wines during red must fermentation. The effect on color and on the formation of derived pigments during fermentation has been studied thoroughly since the 90s. Yeast can increase grape anthocyanin's color by acidification by hyperchromic effect (increase of flavylium molecules). Recent studies with non-Saccharomyces species, as Lachancea thermotolerans, described the intense effect of some strains on anthocyanin's color, and subsequent, stability, by strongly reducing wine's pH during fermentation. Moreover, selected yeast strains of Saccharomyces have been shown to release metabolites such as pyruvic acid or acetaldehyde that promote the formation of vitisin A and B pyranoanthocyanins during must fermentation. Schizosaccharomyces pombe, because of its specific metabolism, can produce higher concentrations of pyruvate, which enhances the formation of vitisin A-type derivatives. The hydroxycinnamate decarboxylase activity that some Saccharomyces strains express during fermentation also promotes the formation of vinylphenolic derivatives. Some non-Saccharomyces species, such as S. pombe or P. guilliermondii can also improve the production of these derivatives compared to selected strains of Saccharomyces cerevisiae. Lastly, some yeasts are also able to modulate the formations of polymeric pigments between grape anthocyanins and flavonoids, such as catechins and procyanidins.

Sonication of Yeast Biomasses to Improve the Ageing on Lees Technique in Red Wines.

Ageing on Lees (AOL) is a technique to improve the aromatic and gustatory complexity of wine, mainly by improving its body and reducing its astringency. However, the autolytic process is slow, resulting in high production costs. This work evaluated the effect of adding sonicated lees and combining it with oak chips, as a new technique to accelerate the AOL process and improve the aromatic quality of aged red wine. Cell disruption due to sonication was verified by optical microscopy. Volatile acidity, total polyphenol index, color intensity, tonality, dissolved oxygen, anthocyanins, and fermentative volatiles were monitored throughout the ageing of the wines. Sensory analysis was performed at the end of the ageing process. Polysaccharides released from the cell walls and the oxygen consumption, was quantified using a hydroalcoholic solution. The results indicated a 20% increase of the polysaccharide content and suggested an increase in the antioxidant capacity of the lees. No significant changes were observed in the fermentative volatile compounds and the total polyphenol index (TPI), except for those wines in contact with wood. The sonication of lees had some protective effect on the total anthocyanins content, however, color intensity was significantly lower in the sonicated treatments. The sonication of the lees did not cause any defect at the sensory level. Therefore, sonication could allow a reduction in the SO2 addition to wine, as well as a shortening of the ageing times.

Use of non-Saccharomyces yeasts and oenological tannin in red winemaking: Influence on colour, aroma and sensorial properties of young wines.

Today, many non-Saccharomyces strains have been verified can be positive for the development of wine anthocyanin and aroma in different fermentation scenarios. Moreover, oenological tannins are widely used in wine industry to improve the colour profile and aroma complexity. The aim of this work is to analyze the fermentation characters of non-Saccharomyces strains and investigate the effects of pre-fermentative addition of oenological tannins on the wine components as well as sensory properties. For this purpose, five selected non-Saccharomyces strains and grape seed tannin were used to carry out the different fermentation trials. As a result, the grape seed tannin were less likely to influence growth kinetics of non-Saccharomyces strains. Schizosaccharomyces pombe has been proved can be effective to reduce the malic acid content while increase the level of vinylphenolic pyranoanthocyanin, which is positive for wine colour stability. Pre-fermentative use of oenological tannin was verified could be beneficial for the wines fermented with non-Saccharomyces regarding the improvement of wine colour, anthocyanin composition and the complexity of volatile compounds. Nevertheless, sensory analysis showed that oenological tannin could be less effective to modify the aroma impression of non-Saccharomyces wines.

Effect of Lachancea thermotolerans on the Formation of Polymeric Pigments during Sequential Fermentation with Schizosaccharosmyces pombe and Saccharomyces cerevisiae.

Anthocyanins in red grape musts may evolve during the winemaking process and wine aging for several different reasons; colour stability and evolution is a complex process that may depend on grape variety, winemaking technology, fermentative yeast selection, co-pigmentation phenomena and polymerization. The condensation of flavanols with anthocyanins may occur either with the flavylium ion or with the hemiacetal formation in order to produce oligomers and polymers. The kinetics of the reaction are enhanced by the presence of metabolic acetaldehyde, promoting the formation of pyranoanthocyanin-type dimers or flavanol-ethyl-anthocyanin structures. The experimental design carried out using white must corrected with the addition of malvidin-3-O-glucoside and flavanols, suggests that non-Saccharomyces yeasts are able to provide increased levels of colour intensity and larger polymeric pigment ratios and polymerization indexes. The selection of non-Saccharomyces genera, in particular Lachancea thermotolerans and Schizosaccharomyces pombe in sequential fermentation, have provided experimental wines with increased fruity esters, as well as producing wines with potential pigment compositions, even though there is an important reduction of total anthocyanins.

The Effects of Pre-Fermentative Addition of Oenological Tannins on Wine Components and Sensorial Qualities of Red Wine.

Today in the wine industry, oenological tannins are widely used to improve wine quality and prevent oxidation in wine aging. With the development of tannin products, new oenological tannins are developed with many specific functions, such as modifying antioxidant effect, colour stabilization and aroma modifications. The aim of this work is to investigate effects of pre-fermentative addition of oenological tannins on wine colour, anthocyanins, volatile compounds and sensorial properties. In this case, Syrah juice was extracted with classic flash thermovinification from fresh must in order to release more colour and tannins. Three types of oenological tannins, which are, respectively, derived from grape skin, seed (Vitis vinifera) and French oak (Quercus robur and Querrus petraea), were selected to carry out the experiments with seven treatments. Results indicated that tannin treatments significantly improved wine aroma complexity and sensorial properties. However, the concentration of some stable pigments such as Vitisin A, Vitisin A-Ac and Vitisin B was negatively affected by tannin additions. Nevertheless, by means of cluster analysis and principal component analysis, it was observed that higher alcohols were significantly promoted by grape seed tannin while most anthocyanins can be improved by addition of grape tannins. In conclusion, low amount of oenological tannin derived from grape seed is a promising method to be applied especially for young red wine making.

Emerging biotechnologies and non-thermal technologies for winemaking in a context of global warming.

In the current situation, wine areas are affected by several problems in a context of global warming: asymmetric maturities, pH increasing, high alcohol degree and flat wines with low freshness and poor aroma profile. The use of emerging biotechnologies allows to control or manage such problems. Emerging non-Saccharomyces as Lachancea thermotolerans are very useful for controlling pH by the formation of stable lactic acid from sugars with a slight concomitant alcohol reduction. Lower pH improves freshness increasing simultaneously microbiological stability. The use of Hanseniaspora spp. (specially H. vineae and H. opuntiae) or Metschnikowia pulcherrima promotes a better aroma complexity and improves wine sensory profile by the expression of a more complex metabolic pattern and the release of extracellular enzymes. Some of them are also compatible or synergic with the acidification by L. thermotolerans, and M. pulcherrima is an interesting biotool for reductive winemaking and bioprotection. The use of bioprotection is a powerful tool in this context, allowing oxidation control by oxygen depletion, the inhibition of some wild microorganisms, improving the implantation of some starters and limiting SO2. This can be complemented with the use of reductive yeast derivatives with high contents of reducing peptides and relevant compounds such as glutathione that also are interesting to reduce SO2. Finally, the use of emerging non-thermal technologies as Ultra High-Pressure Homogenization (UHPH) and Pulsed Light (PL) increases wine stability by microbial control and inactivation of oxidative enzymes, improving the implantation of emerging non-Saccharomyces and lowering SO2 additions. GRAPHICAL ABSTRACT.

Effect of HHP and UHPH High-Pressure Techniques on the Extraction and Stability of Grape and Other Fruit Anthocyanins.

The use of high-pressure technologies is a hot topic in food science because of the potential for a gentle process in which spoilage and pathogenic microorganisms can be eliminated; these technologies also have effects on the extraction, preservation, and modification of some constituents. Whole grapes or bunches can be processed by High Hydrostatic Pressure (HHP), which causes poration of the skin cell walls and rapid diffusion of the anthocyanins into the pulp and seeds in a short treatment time (2-10 min), improving maceration. Grape juice with colloidal skin particles of less than 500 µm processed by Ultra-High Pressure Homogenization (UHPH) is nano-fragmented with high anthocyanin release. Anthocyanins can be rapidly extracted from skins using HHP and cell fragments using UHPH, releasing them and facilitating their diffusion into the liquid quickly. HHP and UHPH techniques are gentle and protective of sensitive molecules such as phenols, terpenes, and vitamins. Both techniques are non-thermal technologies with mild temperatures and residence times. Moreover, UHPH produces an intense inactivation of oxidative enzymes (PPOs), thus preserving the antioxidant activity of grape juices. Both technologies can be applied to juices or concentrates; in addition, HHP can be applied to grapes or bunches. This review provides detailed information on the main features of these novel techniques, their current status in anthocyanin extraction, and their effects on stability and process sustainability.

Contribution of Grape Juice to Develop New Isotonic Drinks With Antioxidant Capacity and Interesting Sensory Properties.

Nowadays, the sector of isotonic beverages has developed its market based on fruit juices that provide a sports drink with antioxidant and biological activities in addition to their principal role of rehydration and replacement of minerals and carbohydrates during physical exercise. Consumption of grape juice is increasing worldwide because of its sensory characteristics and nutritional value. It contains mainly water, sugars, organic acids, and phenolic compounds. Phenolic compounds play a major role in prevention of various diseases through their biological activities linked to antioxidant, anti-inflammation, anticancer, anti-aging, antimicrobial, and cardioprotective properties. Several studies have demonstrated that grape juice is able to improve performances of antioxidant activity, protect against oxidative damage, and reduce inflammation during sports activities. Polyphenol content also provides a great sensory profile, mainly color which is an important indicator for consumers when choosing beverage products. The contribution of grape juice through its nutritional value and sensory properties makes it an alternative for the development of a new isotonic drink that will be a novel and healthy product in the field of healthy beverages.

Elaboration of an organic beverage based on grape juice with positive nutritional properties.

The present study aimed to develop a natural beverage with interesting phytochemical composition and biological activity based on grape juice without added sugars or artificial additives. Two groups of blends were made by diluting concentrate grape juice with a sugar content of 65 °Brix with two different mineral waters (BA: Bezoya with low mineralization; BB: Solan de Cabras with high mineralization). Lemon juice was used for pH correction, and mixtures of extractions of hop with tea and hop with mint were used to increase aroma. Samples were stored under refrigeration (4°C) then subjected to physicochemical and sensory analysis. The results demonstrated that malvidin-3-O-glucoside pigment was the predominant pigment with a concentration ranging from 75.71 ± 12.49 to 84.87 ± 1.70 mg/L. The levels of sugars ranged from 79.90 ± 1.37 to 82.37 ± 0.55 g/L and total soluble solids were between 5.47 ± 0.12 and 5.77 ± 0.06 °Brix. Total acids presented a significant difference, ranging from 1.40 ± 0.00 to 1.43 ± 0.06 g/L in BA samples and from 1.10 ± 0.10 to 1.20 ± 0.00 g/L in BB samples. For 20 days, the color increased in all beverages. However, BA drinks presented higher acidity and higher red color intensity than BB drinks, so the type of water and pH influenced the color of beverages. The sensory evaluation showed that the beverage made with low mineral water and flavored with a mixture of hop with tea was preferred.

Biomodulation of Physicochemical Parameters, Aromas, and Sensory Profile of Craft Beers by Using Non-Saccharomyces Yeasts.

Beer is an alcoholic beverage produced by the metabolism of yeasts and made from water, malt, and hops. In recent years, the interest in craft beers has increased considerably due to the demand for new beverages and the consumer's willingness to pay higher prices. This article explores the sensorial changes produced in craft beers by using different Saccharomyces and non-Saccharomyces yeasts with several instrumental and sensory analyses performed. After a primary fermentation process with Saccharomyces cerevisiae or Lachancea thermotolerans, it was observed that green beer brewed with L. thermotolerans had a lower pH (3.41) due to the significant production of l-lactic acid (3.98 g/L) compared to that brewed with S. cerevisiae. Following, the bottle conditioning was carried out with a culture of S. cerevisiae, L. thermotolerans, Hanseniaspora vineae, or Schizosaccharomyces pombe. Of note is the increased production of aromatic esters, including 2-phenylethyl acetate in the H. vineae conditioning, which is associated with a high aromatic quality, as well as ethyl lactate in all samples, whose main fermentation was carried out with L. thermotolerans. Although this research is at an early stage, future complementary studies may shed more light on this topic.

Co-inoculations of Lachancea thermotolerans with different Hanseniaspora spp.: Acidification, aroma, biocompatibility, and effects of nutrients in wine.

The use of non-Saccharomyces yeast in the winemaking industry and even more their co-inoculations to maximize their growth and to express phenotypic characteristic is gaining more and more relevance. This study aimed to shed light on the biocompatibilities between Lachancea thermotolerans and Hanseniaspora spp., using different types of nutrients and considering the effect on Yeast Assimilable Nitrogen (YAN), at low temperature (16 °C) and medium SO2 (50 mg/L), in white must. L. thermotolerans has been used for its positive effect on pH reduction and Hanseniaspora spp. for improving the sensory profile. The behaviour of these yeasts was evaluated in co-inoculation, always finishing the fermentation with the sequential inoculation of S. cerevisiae. Significant results were obtained on the population count (CFU/mL) in CHROMagar™, with higher populations of Hanseniaspora spp. with respect to L. thermotolerans. Fermentations with L. thermotolerans/H. vineae, showed inhibition of acidification, generating up to 0.41 g/L of lactic acid. On the contrary, a synergistic effect when L. thermotolerans/H. opuntiae was used, achieved 2.44 g/L of lactic acid and a pH reduction of up to 0.16 and always more significant with Nutrient Vit BlancTM. At the same time ethanol concentration decreased by 3.4 % and volatile acidity never exceeded 0.5 g/L. Aromatic composition was analysed and it was found that all fermentations retained more aromatic esters and that on day 7 the amount of 2-phenylethyl acetate was at least 3 times higher in all fermentations compared to the control (Sc + Nutrient Vit BlancTM) which had 5.96 mg/L. Less yellow intensity (-17.3 %) typical of oxidation were observed in all fermentations in which Nutrient Vit BlancTM had been used and in the sensory analysis the co-inoculations with H. vineae generated better scores.

Synergetic Effect of Metschnikowia pulcherrima and Lachancea thermotolerans in Acidification and Aroma Compounds in Airén Wines.

On the one hand, the species Lachancea thermotolerans is known for its high genetic diversity, allowing for the existence of strains that produce high concentrations of lactic acid. In contrast, the species Metschnikowia pulcherrima is renowned for its high enzymatic activity capable of producing aromatic esters during fermentation. By enhancing acidity and boosting the concentration of aromatic compounds, both species are currently used to enhance the organoleptic profile of wines. In this regard, ternary fermentations with M. pulcherrima and L. thermotolerans were carried out and the wines produced were further analysed with GC-FID, FTIR, and UV-Vis spectrophotometry. The outcomes showed that the species M. pulcherrima favored an increase in ethyl lactate (between 37 and 41 mg/L) along with an increased concentration of 2-phenylethyl alcohol (between 30 and 35 mg/L), whereas the species L. thermotolerans was able to produce 1 g/L of lactic acid in ternary fermentations. Additionally, pH levels were slightly lower in these fermentations and the color of the white wines produced showed less chemical oxidation as hue values were lower than the control. Finally, the ternary fermentations of L. thermotolerans and M. pulcherrima had higher overall rating in the tasting. In conclusion, ternary fermentations involving these two non-Saccharomyces species are suggested as a substitute for spontaneous fermentations in the production of wines from neutral varieties to express freshness more vividly. This biotechnology may be further favored by the possibility of applying emerging technologies for the removal of microorganisms in grapes and musts.

Biocompatibility in Ternary Fermentations With Lachancea thermotolerans, Other Non-Saccharomyces and Saccharomyces cerevisiae to Control pH and Improve the Sensory Profile of Wines From Warm Areas.

Global warming is causing serious problems, especially, in warm regions, where musts with excess sugars and high pH produce wines with decreased freshness and unstable evolution. This study aimed to determine biocompatibility between yeast species, the capacity for microbiological acidification, and the aromatic profile produced in ternary fermentations in which Lachancea thermotolerans has been co-inoculated with Hanseniaspora vineae, Torulaspora delbrueckii, or Metschnikowia pulcherrima, and the fermentation process is subsequently completed with sequential inoculation of Saccharomyces cerevisiae. For this purpose, different cell culture media and instruments were used such as infrared spectroscopy, enzymatic autoanalyzer, chromatograph coupled with a flame ionization detector, spectrophotometric analysis, among others. The behavior of these yeasts was evaluated alone and in co-inoculation, always finishing the fermentation with sequential inoculation of S. cerevisiae, at a stable temperature of 16°C and with a low level of sulfites (25 mg/L) in white must. Significant results were obtained in terms of biocompatibility using population counts (CFU/ml) in differential plating media that permitted monitoring. Quantification of the five species was studied. Concerning acidification by L. thermotolerans in co-inoculations, we showed some metabolic interactions, such as the inhibition of acidification when H. vineae/L. thermotolerans were used, generating just over 0.13 g/L of lactic acid and, conversely, a synergistic effect when M. pulcherrima/L. thermotolerans were used, achieving 3.2 g/L of lactic acid and a reduction in pH of up to 0.33. A diminution in alcohol content higher than 0.6% v/v was observed in co-inoculation with the L. thermotolerans/M. pulcherrima yeasts, with total sugar consumption and very slow completion of fermentation in the inoculations with H. vineae and T. delbrueckii. The aromatic composition of the wines obtained was analyzed and a sensory evaluation conducted, and it was found that both L. thermotolerans and co-inoculations retained more aromatic esters over time and had a lower evolution toward the yellow tones typical of oxidation and that the best sensory evaluation was that of the Lt + Mp co-inoculation. Lachancea thermotolerans and co-inoculations produced wines with low levels of volatile acidity (<0.4 g/L). This work shows that good consortia strategies with binary and ternary fermentations of yeast strains can be a powerful bio-tool for producing more complex wines.

Emerging Non-Thermal Technologies for the Extraction of Grape Anthocyanins.

Anthocyanins are flavonoid pigments broadly distributed in plants with great potential to be used as food colorants due to their range of colors, innocuous nature, and positive impact on human health. However, these molecules are unstable and affected by pH changes, oxidation and high temperatures, making it very important to extract them using gentle non-thermal technologies. The use of emerging non-thermal techniques such as High Hydrostatic Pressure (HHP), Ultra High Pressure Homogenization (UHPH), Pulsed Electric Fields (PEFs), Ultrasound (US), irradiation, and Pulsed Light (PL) is currently increasing for many applications in food technology. This article reviews their application, features, advantages and drawbacks in the extraction of anthocyanins from grapes. It shows how extraction can be significantly increased with many of these techniques, while decreasing extraction times and maintaining antioxidant capacity.

Pulsed Electric Fields to Improve the Use of Non-Saccharomyces Starters in Red Wines.

New nonthermal technologies, including pulsed electric fields (PEF), open a new way to generate more natural foods while respecting their organoleptic qualities. PEF can reduce wild yeasts to improve the implantation of other yeasts and generate more desired metabolites. Two PEF treatments were applied; one with an intensity of 5 kV/cm was applied continuously to the must for further colour extraction, and a second treatment only to the must (without skins) after a 24-hour maceration of 17.5 kV/cm intensity, reducing its wild yeast load by up to 2 log CFU/mL, thus comparing the implantation and fermentation of inoculated non-Saccharomyces yeasts. In general, those treated with PEF preserved more total esters and formed more anthocyanins, including vitisin A, due to better implantation of the inoculated yeasts. It should be noted that the yeast Lachancea thermotolerans that had received PEF treatment produced four-fold more lactic acid (3.62 ± 0.84 g/L) than the control of the same yeast, and Hanseniaspora vineae with PEF produced almost three-fold more 2-phenylethyl acetate than the rest. On the other hand, 3-ethoxy-1-propanol was not observed at the end of the fermentation with a Torulaspora delbrueckii (Td) control but in the Td PEF, it was observed (3.17 ± 0.58 mg/L).